Pump for hydraulic systems



M Cfltorneg H. J. MOGOVERN Filed Aug. 3} 1942 PUMP FOR HYDRAULIC SYSTEMSDec. 28, 1943.

Patented Dec. 28, 1943 UNITED STATES PATENT OFFICE Claims.

is a tedious one, and requires a considerable.

amount of time, largely on account of the reaction of the pressurewithin the system, as it gets stronger, until it practically equalizesthe force of the pump. One of the purposes of the present invention isto provide a multiple pump,

of novel construction, which can be used in the usual manner up to thepoint where the pressure.

reaches. a maximum, and worked on a smaller piston capacity for the restof the operation. By this means the time required for the operation isgreatly'lessened.

In its preferred form the device embraces a triple pump system, with acentral. pump or cylinder of relatively large capacity and a pair ofside pumps or cylinders in line with the main.

cylinder, of a smaller diameter, and in line with each other, so thatthe pistons of all three can be operated from one operating lever orbar. For this part of the operation one end of the lever is anchored, sothat the pistons of all the pumps work in unison, but as, the pressureincreases the anchor bar is disconnected, and the. connection of thelever with the piston rod of.

the central pump serves as a fu1crum,upon which the lever is rocked,giving a force-pump action alternately to one and other of the sidecylinders, with a continuation of the lifting operation of the jacks.

The above named, and other features and advantages of the invention willbe more particularly pointed out in the following specification,reference being had to the accompanying drawing, in which Fig. 1 is aplan view of a pump system embodying the invention.

Fig. 2 is a longitudinal section on the line 2--2 of Fig. 1.

The reference number 5 indicates a pump casing, in form of a block,centrally of which is a bore l, connected at its ends with a pair ofchannels 8 and 9, extending lengthwise of the casing, and parallelwitheach other. Mounted in the side of the casing is a cylinder 10,communicating with the bore 7 through a passageand provided at its outerend with a screwthreaded plug I2, in which is slidable the rod I3 of apiston or plunger It. At the sides of the bore 7 are bores l5 and it, ofsmaller diameter, also communicating at their ends with the channels 8and 9.

Mounted in the cylinder 6 in line with the bore I5 is a cylinder ll, ofa diameter corresponding with that of the bore 55, and connectedtherewith through a passage it. In the end of the cylinder I1 is ascrew-threaded plug l9, in which is-slidable a rod 20, on the inner endof which is a piston 2!. At the outer end of the rod 20 is pivotedthereto a link 22, which has a pivotal connection with a hand-lever 23,as at a. The outer end of the rod I3 is'similarly connected with thelever 23 as at b..

A cylinder 24, of similar size and capacity as the cylinder ll, isconnectedwith the bore I6 by a passage 25, and at the outer end of saidcylinder 24 is a threaded plug 26, having an opening in which isslidable a rod 2?, provided on its in-- ner end with a piston 28. Theouter end of the rod 2'! is also provided with a link 29. pivotallyconnected with the lever 23. The lever is anchored at one end by a bar3%), one end of which is rockingly connected with a pin 3| supported atthe. end ofthe casing 6. The outer end of the;

of the casing are united by a passage 33, normally closed at its upperend by a valve mechanism, as hereinafter set forth. Communicating withthe channel 8 is a pair of pipes 35 and-36, each of which connects withone of a pair of hydraulic jacks, not shown herein, but similar to thoseset forth in said former application;- and each provided with a shut-01fcock, as at 3 By this means the movement of hydraulic mes,

dium through one or both of said pipes may be interrupted. The lowerchannel is connected;

with a supply tank 39 by means of a pipe 38, pro-- vided with a cut-outvalve at til. The tank can be supported at any suitable point about atruck or other device containing pressure apparatus. The tank 39 isclosed to the escape of medium in any other direction than through thepipe 38, and the tendency of the action of the pumps is to drive theliquid in the direction of the pipes 35 and 36, and through the same.

In the lower part of the bore 1 is a threaded valve casing 4|, with anopening 42, normally In a similar manner the bores l5 and [B are Lfitted in their lower ends with check-valves 48 and 49, and in theirupper ends with check-valves 50 and 5|. It can be assumed that by thecombined action of the pumps a maximum quantity of the hydraulic mediumcan be forced out through the pipes 35 and 36 to the jacks or otherpressure devices, with a rapid operation thereof.

Up to a certain point'in the operation of the pumps the pressure isincreased, due to the increased resistance in the jacks or rams, orwhatever may be responding to the operative force, until the pressure isso great that the movement of the pistons in the cylinders practicallyceases. When this occurs the rod 30 is disconnected from the end of thelever by swinging the same upwardly, and the operation continued byrocking the lever 23 upon its central pivotal point as a fulcrum. Atthis time the piston I4 is near the outer end of its movement, and isstationary, forming a substantial support upon which the lever isrocked. This results in an alternating movement of the two smallerpistons, with a continued upward movement of the jacks, or object thatis being raised. The amount of pressure exerted against the pistons ismultiplied in proportion to the size thereof, so that the smallerpistons continue to operate after the large one in the center is forcedto be idle. In-case it is desired to cause a greater elevation at oneside of a truck or trailer, or other object, this is accomplished byclosing the pipe 35 or 36 at the other side, causing all of the force to'be exerted in the desired direction.

At one end of the channel 8 is a plug 52, and at the other end is avalve 54, normally closed by a needle-valve 55, having a threaded partrotatable in a plug 56, and provided with a handle 51 for rotation. Whenthe valve 54 is opened the pressure is permitted to escape through thepassage 33, with a gradual return of the hydraulic medium to the supplytank 34, and a consequent gradual return of the jack elementsdownwardly.

What I claim and desire to secure by Letters Patent is:

1. In a pump for hydraulic systems, a casing provided with a pluralityof passages for the, con duct of a volume of hydraulic medium. providedwith an intake in one of its sides and one or more outlets at anotherpoint, a pair of cylinders of varying diameters mounted on said casinproximity to said cylinders, and connections between said pistons andsaid handlever adaptable to a joint operation of said pistons or aseparate operation of the smaller piston fulcrumed upon the largerpiston as a support.

2. In a pump for hydraulic systems, a casing provided with a pluralityof passages for the conduct of a volume of hydraulic medium, including acentral bore of relatively larger size, and side bores of more limitedsize, an intake pipe connected with said passages, and one or moreoutlets for conveying the medium to other mechanisms, a central cylinderof relatively large size communicating with the central bore, andprovided with a piston and rod therefor, side cylinders of less diameterthan the central cylinder provided with pistons and rods correspondingtherewith, a hand-lever operatively connected with said piston-rods, andmeans for holding one end of said hand-lever as a fulcrum therefor, de-

, tachable to permit the rocking of the lever upon the central piston,as a stationary support.

3. In a device of the class described, a casing and bores therein ofvarying sizes, provided at one end with intake check-valves and at theother end with out-let check-valves, a sys tem of channels connectedwith said bores, connected with a hydraulic medium source of supply andhaving one or more outlets for the discharge of said medium, pumpcylinders on said casing communicating with said bores and havingpistons corresponding therewith in size, a hand-lever operativelyconnected with said pistons, an anchor for said hand-lever holding it inposition for joint operation of the pistons, and releasable topermit'the rocking of the lever with the larger piston as a supportingbase.

4. In a pump for hydraulic systems a casing provided with a plurality ofpassages for the conduct of a quantity of hydraulic medium, a supplytank for said passages communicating therewith, two or more cylinders onsaid casing connected with said passages, and of varying capacity,pistons in said cylinders, a hand-lever operatively connected with saidpistons, means for compelling a joint action of the pistons, or anindependent action of those of less capacity, based on the ones ofgreater capacity, one or more outlets for the medium for said casing,and a release mechanism permitting the return of the medium to thesupply tank.

5. In a pump for hydraulic systems, a casing provided with a system ofpassages for a hydraulic medium, an inlet for said medium and supplytank connected with said inlet, one or more outlets for said systemprovided with shut off cocks, a central cylinder of relatively largesize mounted on said casing, provided with a piston and rod therefor,and communicating with said passage system, one or more smaller cylnders mounted on said casing, also communicating with the passagesystem, and provided with pistons and rods therefor, a hand-leveroperatively connected with said rods, and means attachable to said leverto compel the joint operation of said pistons, and releasable therefromto perm t the action of the smaller pistons with the larger pistonserving as a fulcrum support.

HAROLD J. MCGOVERN.

